If I'm angry at a situation, I will typically vent about it with someone until I can wrap my brain around it and figure out if there's a solution or not. If not, venting at least helps.
If I'm angry at a person, especially if that person does or says something that hurts me or makes me feel like I've been treated unfairly, it sends me into a loop where I'm extremely upset, but am trying to look at it from all angles. I think a lot of times, I feel like I'm being pretty considerate and trying to do no harm, and so I feel like I should be treated that way, too. So if I find myself in a situation where I feel even slightly betrayed as far as the rules of "being cool" go, it really does a number on me. I tend to shut down and become very frosty, and usually the other person will have to bring it up again if they want to talk about it, because it feels weird to me to go, "Hey, I didn't like how you did x."
Sometimes it's a relief if someone will just yell, because I don't feel like I have to have all the answers then--I just react in the moment and say my piece.